People saying you can't blame the cops for this one -- yes you can. In the UK, a guy attacked the police with a machete in a far more violent manner, and they took him in alive because of training and proper procedure. Same thing with a guy with a knife this year. They engage, retreat, tire the guy out, use shields, until they can safely subdue him.
US police are all about escalation and shooting someone. Almost 1000 people were shot killed by police last year. That's crazy. If you saw a news report from anywhere else in the world that said "1000 civilians were killed by police last year" you would absolutely believe it was some sort of fascist police state.
People in the US have a real problem objectively looking at their own system.
The police need better training and support, along with higher levels of accountability. I would also argue they need higher pay in order to attract better candidates.